According to WHO statistics, less than 0.007% of all water on the earth is readily accessible for human consumption. About a billion people lack access to safe drinking water. More than 3.5 million people die every year due to water-related diseases. Water insecurity is one of the leading causes for school dropouts, especially among girls, and more than 200 million working hours are spent (almost exclusively by women) daily for the collection of domestic water.
The water crisis is worsened in arid parts of the world due to abuse of groundwater, water-intensive crop cultivation, rapid industrialization, and changing lifestyle. In some dry regions, the appearance of fog in the early morning is common. Fog is a completely untapped water resource. Fog harvesting provides an opportunity to “produce” water locally for rural communities, which will reduce the stress on groundwater. Consider a country like Chile, where a persistent advection fog is occurs due to the long and mountainous coastline. By one estimate, 10 billion m3 of fog water per year is available in Chile. Currently, water consumption in northern Chile is 391 million m3 per year, i.e., only 4% of the total water content in the fog. Water collection from fog harvesting thus has enormous potential to locally satisfy the need for a pure and dependable supply of water in arid locations.